feat(M35): dynamic target configuration with encrypted config, test connection, and GUI updates

Mirror M34's dynamic issuer config pattern for deployment targets: AES-256-GCM
encrypted config storage, sensitive field redaction in API responses, agent
heartbeat-based test connection endpoint, and full frontend updates including
test status indicators, source badges, and removal of stale hostname/status
fields from the Target interface.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

web/src/api/client.test.ts

@@ -36,6 +36,7 @@ import {
   getTargets,
   createTarget,
   deleteTarget,
+  testTargetConnection,
   getProfiles,
   getProfile,
   createProfile,
@@ -425,6 +426,14 @@ describe('API Client', () => {
       expect(url).toBe('/api/v1/targets/t-nginx');
       expect(init.method).toBe('DELETE');
     });
+
+    it('testTargetConnection sends POST', async () => {
+      mockFetch.mockReturnValueOnce(mockJsonResponse({ status: 'success', message: 'Agent is online' }));
+      await testTargetConnection('t-nginx');
+      const [url, init] = mockFetch.mock.calls[0];
+      expect(url).toBe('/api/v1/targets/t-nginx/test');
+      expect(init.method).toBe('POST');
+    });
   });
 
   // ─── Approval ──────────────────────────────────────

web/src/api/client.ts

@@ -232,6 +232,9 @@ export const updateTarget = (id: string, data: Partial<Target>) =>
 export const deleteTarget = (id: string) =>
   fetchJSON<{ message: string }>(`${BASE}/targets/${id}`, { method: 'DELETE' });
 
+export const testTargetConnection = (id: string) =>
+  fetchJSON<{ status: string; message: string }>(`${BASE}/targets/${id}/test`, { method: 'POST' });
+
 // Profiles
 export const getProfiles = (params: Record<string, string> = {}) => {
   const qs = new URLSearchParams({ page: '1', per_page: '50', ...params }).toString();

web/src/api/types.ts

@@ -156,10 +156,12 @@ export interface Target {
   id: string;
   name: string;
   type: string;
-  hostname: string;
   agent_id: string;
   config: Record<string, unknown>;
-  status: string;
+  enabled: boolean;
+  last_tested_at?: string;
+  test_status?: string;
+  source?: string;
   created_at: string;
   updated_at?: string;
 }